There are people who walk through this life absolutely sure of everything before them - their job, their marriage, their lifestyle, their friends, their place in the universe, their purpose for existing, their destiny. They even know what they will be wearing to work tomorrow, and it is only 6 p.m. the night before.

If we were all like this, half the screenwriters in Hollywood would have nothing to say. Novelists would have to resort to writing how-to books to fill their blank pages.

The world would be a dull place.

Next to alcohol, insecurity is probably the leading cause of failure for relationships.

Consider Michael (Zach Braff) in the fairly unromantic "The Last Kiss" (Paramount, 3 stars). He's a 29-year-old architect living in Wisconsin with the beautiful Jenna (Jacinda Barrett) who is studying for her doctoral presentation. Michael's lifetime buddies pay Jenna the ultimate compliment when they say "She's like a guy."

Except that she's pregnant.

Prior to the pregnancy, only the word "marriage" could turn Michael's blood cold. Now he's in full emotional freak-out.

With exquisite timing, into Michael's life comes Kim (Rachel Bilson), a willowy and sensuous university sophomore who, for some reason thinks that Michael is hot. (Yes, that Zach Braff - the unmade bed as sex symbol.)

"I could be your last chance at happiness," she tells Michael with breathy seduction.

Michael succumbs. Fairly easily. And Jenna is no dope. She's on to the affair almost before it happens.

Which is surprising because she's distracted by the sudden implosion of her parents' marriage of 30 years. Anna (Blythe Danner), it seems, has decided she's never loved Stephen (Tom Wilkinson, who is a master at portraying the gentle put-upon husband).

Then there are Michael's boyhood friends. Chris (Casey Affleck) is in a disintegrating marriage with the mother of his child. Izzy (Michael Weston) is obsessed with the woman who dumped him. Kenny (Eric Christian Olsen) is a single guy who tends bar and beds women - which is a lot of work.

Basically everyone in this movie (with the exception of Kenny) is in emotional crisis mode. None is happy with what they have, save Jenna until she discovers Michael's indiscretion. A good part of the movie is taken up with Michael's quest to earn back Jenna's love and trust. Not an easy task.

While the potential is great, there is no cheap comedy here. Paul Haggis adapted the story from Gabriele Muccino's "L'ultimo Bacio." Actually "The Last Kiss" is a pretty thoughtful look at the traumas of coming of age and the pitfalls that await you when you've been "of age" for a very long time.

When Michael professes to Jenna's father that, despite his affair, he really loves her, Stephen (who has only just learned of his own wife's indiscretions) grows impatient. It's not about love, he shoots back. "It's what you do to the people you love that counts."

The DVD includes a commentary track from Braff and director Tony Goldwyn. Other cast members join these two on a second commentary track. There are also several features on the making of the movie, seven deleted or extended scenes, a gag reel and a music video.

ALSO THIS WEEK

"Jackass Number Two" (Paramount, 1 star) Stupid people do more stupid stuff and laugh uproariously at themselves. What more can I say? Somebody pays them to do it and they've got an audience for it. But that's not my problem.

"The Black Dahlia" (Universal, 2 stars) It is a mystery that won't be solved nor will it disappear. In 1947, a young actress is found dead in a vacant Hollywood lot. Her corpse has been cut in half and she is mutilated. The real story transfixed the world for a time but when no arrests were made, it settled into hard-boiled pop cultural history. Were that this movie could be so compelling. It's another Brian De Palma cinematic trompe l'oeil with touches of noir and tributes to directors past. There are also, to put it politely, very subtle performances from minimalist performers like Scarlett Johansson and Josh Hartnett. The murder mystery loses ground to the character studies and in the end, De Palma and the views must hustle to make sense of it all.

"Checking Out" (Allumination FilmWorks, 2 stars) Peter Falk is a retired vaudeville actor who is planning - and I've got to go to the press sheet here because I can't make this stuff up - "his own 'Big Fat Jewish Suicide.'" The film is then described as a "light-hearted comedy." Oy vey!

"The Descent" (Lionsgate, 1 star) Let's flush that holiday spirit right out of the system with a "masterpiece of modern horror" on the day after Christmas. Six women take their annual extreme vacation together, exploring a cave in the Appalachian forest. When their exit is blocked, the women press deeper into the abyss - but there is something else lurking in the shadows.

IT CAME FROM TV

"Two-A-Days: Hoover High" (Paramount/MTV, Season 1, three discs) All nine episodes following the Alabama high school's fortunes and misfortunes on and off the gridiron.

"The Simple Life: Til Death Do Us Part" (Fox, one dual-sided disc, 10 episodes) Title takes on whole new immediacy after Nicole Richie's recent wrong-way drive down a Los Angeles freeway.